ABSTRACT An accurate and predictive model of the function and dynamics of any neural circuit requires a complete picture of the synaptic connections between all of its composite cell types. Despite extensive work, we still lack such a diagram in V1, or for any other neural circuit in the mammalian central nervous system. The goal of the Neural Connectivity Resource Core is to combine in vivo multiphoton optogenetic circuit mapping with functional calcium imaging and post-hoc seqFISH RNA profiling to obtain the functional connectome of all transcriptionally distinguishable V1 cell types ? that is a complete connectivity diagram between all of V1?s component cell types, specifically including data on the strength and short-term plasticity of the unitary monosynaptic connections between each cell type. It will thus provide critical support to the theoretical modeling projects that require these data to build accurate models of V1 dynamics. Furthermore, by working in vivo, this resource core will map synaptic connectivity onto neurons that will also be functionally characterized with respect to their responses to visual stimuli. This will permit direct correlation between visual responses, synaptic connectivity and dynamics, and transcriptional identity at the cellular level. This knowledge is critical for constraining our development of the most accurate and predictive theoretical models of visual cortical dynamics and computation.